Look for a folder that fits your function. Do you plan to wear on top of your shirt like a convention pocket? When I travel I perfer one that is hidden. I designed my own out of soft muslin. I made a simple rectangle with a zipper at the top. I sewed a length of binding along the top of the case and a little extra length and put snaps on both ends. The snap part went around my bra straps and then snapped. I tucked the bottom of the pouch into the top of my bra and I had easy access to the zip from my shirt cleavage. I used mine to hold my passport and my travellers checks.

Hint ... make it and start wearing it fully loaded around home and when going shopping.
That way you can find out if it's comfortable for you, test the accessability and see if it is invisible enough to you from the outside or if it sticks out and gives you different shapes you might not want!